A bridge bearing is a part of a bridge which typically supply a resting surface between bridge piers and the bridge deck.
The main purpose of a bridge bearing is to authorize controlled movement and accordingly reduce the stresses combine. Possible causes of movement are thermal expansion and contraction, creep, shrinkage, or fatigue due to the assets of the material used for the bearing. External sources of movement include the agreement of the ground below, thermal expansion, and seismic activity.
There are various different types of bridge bearings which are used depending on a number of unlike factors including the bridge span, loading conditions, and achievement specifications.
The elderly form of bridge bearing is simply two plates resting on top of each other. A general form of modern bridge bearing is the elastomeric bridge bearing. Additional type of bridge bearing is the mechanical bridge bearing. There are various types of mechanical bridge bearing, such as the pinned bearing, which in turn includes specific types such as the rocker bearing, and the roller bearing. Different type of mechanical bearing is the fixed bearing, which allows rotation, but not other forms of movement.
Types of bridge bearing
Steel bearings (flat bearings, curved bearings, rocker bearings, and roller bearings): Forces through steel contact surfaces. Bearing displacement is specially achieved by rolling steel and steel.
PTFE bearing (sliding bearing): The seat adopts PTFE and steel plate as the relative sliding surface of the bearing, and the sliding friction coefficient is much smaller than that of steel and steel.
Rubber bearings (plate rubber bearings, basin rubber bearings, PTFE plate-type rubber seats): The bearing force is achieved by a rubber plate. The movement of the carrier is achieved by sliding of PTFE or the shearing of rubber, and the supporting angle is deformed by the compression of rubber.
Concrete bearings (concrete hinge seats). Lead support: The strength part is composed of hard lead. As per to the structure of the bearing type, it can be normally divided into curved bearings, rock shaft bearings, roller bearings, plate rubber bearings, PTFE plate rubber bearings, basin rubber bearings, spherical bearings and so on. The bearings will be described separately below. Bearings are structural part that withstand high stresses. The load of the superstructure is concentrated in very small areas by the bearings. The reaction force of the roller bearing passes the linear contact force linking the roller and the rolling surface, and the force flow construct a significant stress consolidation phenomenon, which makes the contact surface bear high contact stress. And plate rubber bearings, tank rubber bearings, and spherical bearings and other bearings transmit reaction force, through the plane to the plane, the transmission is smooth, no strong flow necking phenomenon, which is a more reasonable power mode.